1. Field of the Invention
The present invention relates to an object detection system which automatically detects an intruding object by using image devices, such as visible light cameras, near- and far-infrared cameras and millimeter-wave cameras, and also millimeter-wave sensors and laser sensors.
2. Description of the Related Art
Conventional object detection systems detect an object by either processing images from a visible light camera, or processing videos from a near- or far-infrared camera and a millimeter-wave camera, or detecting an object with a millimeter-wave sensor or laser sensor and determining the presence or absence of the object and its position. One of these processes is chosen according to the use.
As technologies related to this invention, there have been known those technologies that detect an object based on videos picked up by a visible light camera and an infrared camera at almost the same angle of view (refer to the following patent document 1 to 5 for example).    Patent document 1: JP-A-3-182185    Patent document 2: JP-A-2007-45336    Patent document 3: JP-A-2002-157599    Patent document 4: JP-A-10-255019    Patent document 5: JP-A-62-204381
However, since a variety of imaging devices and sensors used in the conventional object detection systems have different sensitive wavelength ranges and therefore different detection performances depending on an object to be detected, environmental conditions and sunlight, they have latent factors for erroneous operations.
That is, various imaging devices have their own weak points in detection performance. So a system using such image devices as is cannot be adopted for applications that require a stable detection performance under complex conditions, such as detection of pedestrians at a crossing, detection of a person who has fallen off a station platform and detection of obstacles on railroad tracks and crossings.